1. Field of Invention
The present invention relates to apparatus for removing a tie wire, known as a preform, from an electrical power distribution conductor.
2. Description of the Prior Art
Commonly owned U.S. Pat. No. 5,125,437, of which applicant is inventor, relates to removal of a protective wrapping from a live electrical power conductor. Structure according to this patent has solved certain problems encountered by line crews and has been accepted and widely used. However, experience has shown that several problems still remained when this structure was used.
For example, the structure of this patent required two manipulator poles or hot sticks, with engaging hooks of the conventional type at their ends, be used when removing preforms, particularly when attaching the base and cover portions of the remover onto the conductor. One pole was required to move and manipulate the cover member onto the conductor. Another pole was required to position the base member on the conductor. A number of utilities for safety reasons did not allow a line crew member working on a power line to handle more than one hot stick at any time. Thus, two crew members would often be required for use of this type of preform remover.
There were times when fitting this type of preform remover on a cable could be a problem. Preform removers of this prior type were sized for particular cable diameters. Thus, for a typical utility with several connector sizes, a number of remover tools would be required for a service crew truck. Storage space on trucks has often been quite limited, and the requirement for a different tool for each cable caused space problems on the service truck.
Also, although a precision fit of the preform remover on the conductor was not mandatory, problems occurred when the preform remover was either too tightly or too loosely fitted onto the conductor. When the fit was tight, rotation of the preform remover on the cable was difficult. Situations have occurred when the perform remover would bind so tightly on the conductor that rotation did not occur even before removing the preform. In some instances, the preform remover has become so tightly bound on the conductor that its removal presented a problem. When the preform remover was too loosely fitted onto the conductor, there was also the possibility of inadequate grip or leverage to pry or twist the preform loose from the conductor.